Acoustic Design, Construction and g ,Testing of Fisheries Research Vessels
One dark and stormy day…..
The End
Ray FischeryNoise Control Engineering Inc.
nonoise@noise-control com
April 2010
nonoise@noise control.com
FRV Acoustic Design - OverviewFRV Acoustic Design Overview
• ICES spec – narrow band v TOB (measurement p (procedure)
• Lessons learned• NC approach• NC approach –
– N&V Control Plan – Schedule, approach, deliverables– Detail design – CAD, accuracy– Treatment optimization – trade-offs– Design changes - evaluation
• Shipyard Training• Shipyard Training• QA• Testing
April 2010
g
NCE Experience - ICESNCE Experience ICES
• NOAA FRV-40 (4 delivered)NOAA FRV 40 (4 delivered)• Univ. of Delaware – R/V HUGH R SHARP• Machinery test and overside test– GO SARSMachinery test and overside test GO SARS• Machinery test – JAMES COOK• Reviewed Designer NOISE model of Spanish• Reviewed Designer NOISE model of Spanish
FRV• ARRV – Preliminary Design & UAF agent• ARRV – Preliminary Design & UAF agent• RCRV – Preliminary Design• Taiwan Research VesselApril 2010
• Taiwan Research Vessel
ICES LimitICES LimitICES Radaited Noise Requirement - 11 kts
160
These 2 curves are equivalent!!!!!
140
150Minimize fish reaction
120
130
mic
roPa
@1m
However measurements are done i thi d t b d ICES
100
110
Lp d
B re
1 m
ICES Third Octave Band
in third-octave bands per ICES
80
90
ICES Narrow Band
Sonar Performance
April 2010
10 100 1000 10000 100000
Freq (Hz)
ShipD i
SourceLevels
T t t
QualityControlNOISE
PROCESS
InspectionProcedure
DesignInformation
DesignPracticesFRV
AcousticAnalyses:
ASAP
TreatmentDesign/
Specification
Vendor/Producability
R
Trials
FLOW DIAGRAM
DesignerNOISEPracticesFRV
AcousticSpecification
FRV
Control Plan
CriteriaMet
No
Response
DrawingReview
Yes
PerformanceCriteria
Acoustic
Yes
No
No
ParallelProcess
EquipmentPurchase
FRVSpecifiedAcoustic
Treatments
SelectTreatment
OptimalSystem
Yes
No
Yes
Treatment
Revise
No
Training/TreatmentInstallationProcedures
Yes
Limits Met
DiagnosticTesting
PurchaseSpecification/Budget/FAT
SystemApproach
TreatmentDesign/
I i
Yes
Implementation
TreatmentPerformanceEvaluation/Equip. Test
CorrectiveAction
Integration
AcousticAnalysis:
ASAPNo
PerformanceCriteria
No
Process
Decision
Data
Predefinedprocess
April 2010Criteria
Met
RemedialAction KEY
MACHINERY PROPELLER FLOW
A/BVEHICLE RADIATED NOISE FLOW CHART
FOUNDATION
ENCLOSURE ISOLATORSEA CONNECTED
AIRINJECTION
HULLCOATING
MACHINERY PROPELLER FLOW
S/B
FOUNDATION
NOISETREATMENT
HULLCOATING
APPENDAGES
DECK, BULKHEADVIBRATION
NOISETREATMENT
HULL/
NOISETREATMENT
HULL/SHELL
NOISETREATMENT
1/31/2008 N i C l E i i I
AIRBORNE NOISE U/W RADIATEDNOISE SONAR SELF NOISE
April 2010
1/31/2008 Noise Control Engineering, Inc.
SHIP’S UW SIGNATURESHIP S UW SIGNATURE• Propeller – controls signature when cavitatingp g g
– Cavitation – ICES – Cavitation free to 12 kts– AZIPOD – unacceptable for low noise vessel– Bow Thrusters – not operational for FRV quiet modeBow Thrusters not operational for FRV quiet mode
• Machinery Noise– Propulsion Diesels or Motors
Diesel Generators– Diesel Generators– Large Reciprocating Machinery, Air Compressors
• Sea Connected Systems– Main Seawater Cooling– Auxiliary Seawater Cooling
April 2010
Propeller Noise – CavitationPropeller Noise Cavitation…… is the vaporization
f d Unsteady Sheetof water due to a decrease of the local pressure. This generates millions
Unsteady SheetCavitation
generates millions of very small vapor bubbles whose collapse generates i ifi tsignificant
underwater noise.
Vortex
April 2010
Paths for Machinery NoisePaths for Machinery Noise
• Airborne• First• First
Structureborne• Secondary
Structureborne• U/W Radiated• U/W Radiated
Noise
April 2010
OSCAR DYSON; Vessel Particulars.
Length 64 metersLength 64 metersBeam 15 meters
Draft 6 meters (centerboard retracted), 9.2 meters Draft (centerboard extended)Displacement 2479 metric tons
Speed 14 knots (sustained) 11 knots (maximum quiet speed)Speed 14 knots (sustained), 11 knots (maximum quiet speed)
Diesel Generators
Two Caterpillar 3508 (910 kW, 1800 rpm) & Two Caterpillar 3516 (1360 kW, 1800 rpm)
Propulsion Motor Two tandem 1950 kW @ 128 rpm
April 2010
Propeller Five blade, skewed
OSCAR DYSON; Summary of Noise Control Treatments.; y
Low Noise Equipment Propulsion Motor & Propeller Specially DesignedEquipment
Double Stage Vibration Isolation
Diesel Generators & Reciprocating Equipment3512 system – 18,113 kg; 3508 system – 14,770 kg
Single Stage Vibration Isolation Auxiliary Equipment & HVAC
Acoustic Insulation Perimeter of Engine Room and other noisy spaces
Damping Tiles Applied to hull and bulkheads – constrained layeramping iles pp ed o u a d bu eads co s a ed aye
Hull & Propeller Specially designed by U.S. Navy (NSWC)
April 2010
Specified Intermediate Mass D iDesign
• Space problem –– Height and width
Bad to mix ‘performance’ and ‘hardware’ specification
April 2010
specification
April 2010
Genset Factory Acceptance TestGO SARS has 2 stage isolated diesel; single stage isolated generator. GO SARS has lower level diesel vibration.
April 201010% of genset mass in each block
Cat 3508 1st Skid Mode at 110.9 Hz
April 2010
April 2010
Vendor Weight SNAFUVendor Weight SNAFU
Cat 3512 Genset lbs kg
Scaled wt of Dyson/Bigelow 3512 34610 15732
Design weight 28178 12808Design weight 28178 12808
Delta 6432 2924
123%
N.B.: Wrong Center of Gravity also provided
April 2010
FEA Model – Resonance avoidance & forced response (habitability vibration)(habitability vibration)
April 2010
3rd Hull Mode = 8 Hz
Transverse Bending
April 2010
POTENTIAL RESONANCE
April 2010
NSWCCD design -GFI
Even a little marine growth will cause cavitation below 11 k t
April 2010
knots.
Noise Prediction MethodsU CAD t l t di t h ll ib ti• Use CAD tool to predict hull vibration from all machinery over airborne & t t b th (i l distructureborne paths (including
‘secondary structureborne’ path.• Predict Underwater Noise by applying
Hull Vibration-to-UW noise “Transfer Function” (unclassified).
April 2010
Designer NOISE™ 3 D MODELDesigner NOISE™ 3-D MODEL
April 2010
SOURCE/PATH WEIGHTINGSource Transmission Path
SOURCE/PATH WEIGHTING
ReceiverAirborne
Structure-borne
SecondaryStructure-
borne Total3508 P t
Dry Lab3508 Port
D/G 53 42 41 533508 Stbd
D/G 52 38 41 52D/G 52 38 41 523512 Port
D/G 55 39 44 563512 Stbd3512 Stbd
D/G 54 35 43 54DC Motor 26 14 23 28All S 59 45 49 60
April 2010
All Sources 59 45 49 60
Noise Levels on FRV-40
Compartment Measured Level, dB(A)
Predicted Level, dB(A)
Aft Staterooms 58 56
April 2010Forward
Staterooms51 49
Sea Connected Systems –Fl idB N iFluidBorne Noise
P mp generatedPump generated fluidborne acoustic energy travels viaenergy travels via piping systems.
April 2010
FRV-40 – Isolated AuxiliariesFRV 40 Isolated AuxiliariesTransformer Axial Fan
Egg Sampling Pump Scientific Seawater Pump
April 2010
FRV-40 –T i l I l i STypical Isolation System
Pipe Clamps
Vibration Isolators
“Dog-Leg” Flexible Pipe HosesHoses
April 2010
FRV-40 – Pipe ClampsFRV 40 Pipe Clamps
April 2010
HOW DID THIS HAPPEN?!?
April 2010
April 2010
April 2010
FRV-40 – Required TestingFRV 40 Required Testing• Machinery Vibration in FactoryMachinery Vibration in Factory• Machinery Noise in Factory
Machinery Vibration in Ship• Machinery Vibration in Ship• Airborne Noise in all Ship Spaces• Structural Vibration in Ship (wide)• Sonar Self NoiseSo a Se o se• Underwater Radiated Noise • NB: New ASA S12 64 2009 meas’t std
April 2010
• NB: New ASA S12.64-2009 meas t std.
RADIATED NOISE TESTRADIATED NOISE TEST
April 2010
RADIATED NOISE SIGNATURENOAA FRV-40 UNDERWATER NOISE SURVEY:
Vessel Speed: 11 Knots
160
150
eter
140
mic
ro-P
a @
1 m
e
120
130
Lp, d
B re
1 m
NCE-GOMNSWC-AUTECICES Crit
110
120
10 100 1 000 10 000 100 000
ICES Crit
April 2010
10 100 1,000 10,000 100,0001/3 Octave Band Center Frequency, Hertz
R/V HUGH R. SHARPUniversity of Delaware
OWNER: Univ. of Delaware, College of Marine SciencesMISSION: General ResearchBUILDER: Dakota Creek, Industries (Anacortes, WA)
April 2010
, ( , )DESIGNER: Bay Marine, Inc. (Barrington, RI)DELIEVERY: January 2006
R/V SHARP – Design FeaturesR/V SHARP Design Features
• Meet ICES Limit at 8 knots• Meet ICES Limit at 8 knots• Diesel Electric Plant• Double Isolated Diesel Generators• Isolated ASIR DC Motors• Isolated Schottel Z-Drives• Isolated Auxiliary Machinery• Isolated Auxiliary Machinery • Retractable Transducer Pod
April 2010
R/V SHARP - ProfileR/V SHARP Profile
Engine Room
Bulbous Bow
Schottel Z Drive
Transducer Pod
April 2010
R/V SHARP – Floating DeckDiDiagram
Double Stage Isolated DieselsDiesels
Single Stage Isolated Diesels
Floating Deck
April 2010
Diesels
April 2010
R/V SHARP – Floating Deck
Acoustic Insulation
Damping Tiles
Vibration Isolator
Acoustic Insulation
April 2010
Damping Tiles
R/V SHARP – Floating DeckT i i L (TL)Transmission Loss (TL)
R/V SHARP: Floating Deck Performance (8 knots)
60
70
Upper StageLower StageTotal Reductionx
40
50
on L
oss
(TL)
, dB
x
Floating Deck
20
30
Tran
smis
sio
xx
Floating Deck during construction
0
10
32 63 125 250 500 1000 2000 4000 80001/3 Octave Band Center Frequency, Hz
April 2010
q y,
FRV Mount Performance
R/V SHARP – Damping TilesR/V SHARP Damping Tiles
April 2010
SummarySummary• Comprehensive acoustic control plan needed p p
– Design– Construction– Testing– Testing
• Use of an accurate 3-D noise modeling, empirical and FEA tools allowed:– treatment types and areas of coverage to be
optimized– thereby reducing weight, cost and space required and
T t l C t f O hiTotal Cost of Ownership.• Result - vessels with low acoustic signature and
low noise/vibration onboard environment
April 2010
Things to considerThings to consider• Require the use of expert with direct experience
ith ti d i f FRVwith acoustic design of FRVs• Require the use of CAD acoustic modeling such
as Designer NOISE or equalas Designer NOISE or equal• Require Noise & Vibration Control Plans and
detailed analysis, addressing ice strengtheningy , g g g• Define criterion (NB v TOB), deliverables, test
verification methods, penalties/incentives• Check weights of critical items• QA – construction inspections
April 2010
